OT: Found In Milk and Water Perchlorate Affects Women's Thyroids

Discussion in 'Fibromyalgia Main Forum' started by kjfms, Oct 6, 2006.

  1. kjfms

    kjfms Member

    Original page:
    http://www.webmd.com/content/Article/128/117020.htm



    Pollutant Affects Women's Thyroids

    CDC Study Shows Exposure to Rocket Fuel Ingredient Has Impact on Hormone Levels By Todd Zwillich


    WebMD Medical News Reviewed By Michael Smith, MD
    on Thursday, October 05, 2006

    Oct. 5, 2006 -- Environmental exposure to a common pollutant found in milk and drinking water appears to directly affect hormone levels in women.

    Researchers of a CDC study say they were surprised by their findings that the chemical, called perchlorate, consistently hinders thyroid function after women consume everyday doses in food and water.

    Perchlorate, used in rocket fuel, is widely known to damage the thyroid of animals at high doses in laboratory studies. But scientists, environmental groups, and the defense industry have long been at odds over whether it poses a health risk at relatively low levels found in the environment.

    "We thought the low levels would lead to very low or trivial effects and that happened not to be the case," James L. Pirkle, PhD, tells WebMD. Pirkle is the deputy director for science at the CDC's Environmental Health Laboratory.

    Perchlorate can alter hormone levels by partially blocking absorption of iodide in the thyroid.

    Iodide is a chemical that's vital for the production of thyroid hormone.

    Blocking iodide absorption can lead to hypothyroidism -- an underactive thyroid -- and goiter in adults.

    A dysfunctional thyroid during pregnancy can lead to abnormal brain development and preterm birth in children.

    Hormone Effects

    In the study, researchers found that rising levels of perchlorate in the urine of 1,111 women were directly linked to rising levels of thyroid stimulating hormone (TSH), an indication of an underactive thyroid.

    The effect was even stronger in women with iodide deficiency, which affects roughly one-third of the population.

    In those women, perchlorate exposure was linked to consistent decreases in the thyroid hormone known as thyroxine -- again, consistent with hypothyroidism.

    The study found no similar result in men.

    Pirkle says the findings suggest that everyday perchlorate exposure in the general population has "a small to medium effect" on women's thyroid functioning.

    He said the surprising results were fueled mostly by the use of a new, highly sensitive perchlorate test.

    "We really felt like at these low levels we were not going to see an effect," he says.


    Iodide's Protective Effects

    The study's findings suggest that women can protect themselves against the effects of perchlorate exposure by "just maintaining an adequate level of iodide in the diet," Pirkle says.

    About a half-teaspoon of iodized salt per day is considered enough to raise iodide to normal levels in most adults.

    Gregory Brent, MD, who chaired a 2005 National Academy of Sciences panel on potential health effects of perchlorate, calls Thursday's study "important."

    Based on the study, Brent says, "it's fair" to conclude that environmental levels of perchlorate have the potential to affect human health.

    But since the results did not extend to men, "there should be a caution about how generalizable the results are," says Brent, a professor of physiology at the University of Southern California.

    Setting Limits

    Perchlorate is found in solid rocket propellant but also occurs naturally.

    In 2005, the Environmental Protection Agency (EPA) set a safe limit for perchlorate in drinking water at 24.5 parts per billion (ppb), though regulators have not yet enacted drinking water standards for the chemical.

    This summer, Massachusetts set a drinking water standard at 2 ppb.

    EPA spokesman Dale Kemery says the agency is looking at the possibility of additional study of perchlorate but that there are no plans to revise the existing perchlorate limit.

    He says the "EPA is interested in the CDC's findings, although CDC scientists recommend that their study be confirmed with additional research."

    The Environmental Working Group, a regulatory watchdog organization, says in a statement that 44 million women with low iodide or who are pregnant are at potential risk of perchlorate health effects.

    "This new study shows that even very small levels of perchlorate in water or food can have a marked effect on thyroid levels in women.

    We can't ignore this serious public health issue any longer," says Renee Sharp, an analyst with the group.

    Industry groups have long maintained that perchlorate pollution in the environment poses no risk to humans.

    The National Defense Industrial Association did not respond to requests for a comment.

    "One of the unknown issues is how much perchlorate is out there in the environment," Brent says.


    --------------------------------------------------------------------------------

    SOURCES: Blount, B. Environmental Health Perspectives, online edition, Oct. 5, 2006. James L. Pirkle, PhD, deputy director for science, Environmental Health Laboratory, CDC. Dale Kemery, spokesman, Environmental Protection Agency. Gregory Brent, MD, professor of physiology, University of Southern California. Renee Sharp, analyst, Environmental Working Group.



    [This Message was Edited on 10/06/2006]
  2. gypsy101

    gypsy101 New Member

    We are dairy free. Milk is poison. All dairy is bad for you.
  3. kjfms

    kjfms Member

    Perchlorates are the salts derived from perchloric acid (HClO4). They occur both naturally and through manufacturing.

    They have been used as a medicine for more than 50 years to treat thyroid gland disorders.

    They are also used as an oxidizer in rocket fuel and can be found in airbags, fireworks, and Chilean fertilizers. Both potassium perchlorate (KClO4) and ammonium perchlorate (NH4ClO4) are used extensively within the pyrotechnics industry, whereas ammonium perchlorate is a component of solid rocket fuel.

    Lithium perchlorate, which decomposes exothermically to give oxygen, is used in oxygen "candles" on spacecraft, submarines and in other esoteric situations where a reliable backup or supplementary oxygen supply is needed. Most perchlorate salts are soluble in water.

    Environmental presence:

    Low levels of perchlorate have been detected in both drinking water and groundwater in 35 states in the US according to the Environmental Protection Agency.

    In 2004, the chemical was also found in cow's milk in the area with an average level of 1.3 parts per billion ("ppb" or µg/L), which may have entered the cows through feeding on crops that had exposure to water containing perchlorates.[1] According to the Impact Area Groundwater Study Program [2], the chemical has been detected as high as 5 µg/L in Massachusetts, well over the state regulation of 1 µg/L.

    In some places it is being detected because of contamination from industrial sites that use or manufacture perchlorate.

    In other places, there is no clear source of perchlorate. In those areas it may be naturally occurring or could be present because of the use of Chilean fertilizers, which were imported to the U.S. by the hundreds of tons in the early 19th century.

    One recent area of research has even suggested that perchlorate can be created when lightning strikes a body of water, and perchlorates are created as a byproduct of chlorine generators used in swimming pool chlorination systems.

    As of 2006, the EPA has not yet determined whether perchlorate is present at sufficient levels in the environment to require a nationwide regulation on how much should be allowed in drinking water.

    In 2005, U.S. EPA issued a recommended Drinking Water Equivalent Level (DWEL) for perchlorate of 24.5 µg/L. In early 2006, EPA issued a “Cleanup Guidance” for this same amount. Both the DWEL and the Cleanup Guidance were based on a thorough review of the existing research by the National Academy of Science (NAS).

    This followed numerous other studies, including one which suggested human breast milk had an average of 10.5 µg/L of perchlorate.

    Both the Pentagon and some environmental groups have voiced questions about the NAS report, but no credible science has emerged to challenge the NAS findings.


    Health effects:

    At high levels, above 0.007 milligrams per kilogram per day (mg/kg-d) according to the NAS, perchlorate can temporarily and reversibly inhibit the thyroid gland’s ability to absorb iodine from the bloodstream ("iodide uptake inhibition").

    This dose is conventionally converted into a "drinking water equivalent level" of 245 ppb by assuming a person weighs 70 kilograms (154 pounds) and consumes 2 liters (68 ounces) of drinking water per day over a lifetime.[citation needed]

    This conversion overstates typical exposure because the numerator in the ratio (weight) is below average adult body weight and the denominator in the ratio (daily drinking water consumption) is above the average amount of drinking water adults consume.

    Drinking water in the U.S. contains no more than a few ppb perchlorate--typically less than 10 ppb and rarely as much as 25 ppb.[citation needed]

    At this upper-end concentration, a person could consume 20 liters of drinking water per day before beginning to experience iodide uptake inhibition.

    Of course, drinking 20 liters of water (5.3 gallons!) during one day almost certainly would be fatal.

    While the thyroid uses iodine to produce hormones, NAS says this process of iodide uptake inhibition is not an "adverse," or harmful, affect.

    There has been some speculation that exposure to extremely high doses of perchlorate, for several months or years could lead to hypothyroidism, but NAS found that iodide uptake inhibition was the only consistently documented health effect of perchlorate in humans.[citation needed]

    The NAS also found that perchlorate only affects the thyroid gland.

    There is no evidence that it causes brain damage, birth defects or cancer in humans. It is also not stored in the body, it is not metabolized, and any effects of perchlorate on the thyroid gland are fully reversible once exposure stops.

    There has been some concern on perchlorates effects on fetuses, newborns and children, but several peer-reviewed studies on children and newborns also provide reason to believe that low levels of perchlorate do not pose a threat to these populations.

    On October 1, 2004, the American Thyroid Association (ATA) reported that perchlorate may not be as harmful to newborns, pregnant women and other adults as previously thought.

    Despite having concluded that iodide uptake inhibition is not harmful and that it does not occur at exposures below 245 ppb, the NAS divided by a safety factor of 10 to derive a recommended “reference dose” of 0.0007 mg/kg-d and declared this would be protective of even the most sensitive subpopulations.

    Using the 70 kg body weight and 2 liter/day assumptions used above, this dose is conventionally converted to 25 ppb in drinking water.

    For that reason, most media reports call this the "safe" level of exposure. Some reports use 24.5 ppb, but this level of precision is meaningless given the 10-fold safety factor and the fact that iodide uptake inhibition itself is not harmful.

    The NAS report also stated additional research would be helpful, but emphasized that the existing database on perchlorate was sufficient to make its reference dose recommendation and ensure it would be protective for everyone.


    Types of perchlorates:

    Ammonium perchlorate, NH4ClO4
    Caesium perchlorate, CsClO4
    Lithium perchlorate, LiClO4
    Magnesium perchlorate, Mg(ClO4)2
    Perchloric acid, HClO4
    Potassium perchlorate, KClO4
    Rubidium perchlorate, RbClO4
    Silver perchlorate, AgClO4
    Sodium perchlorate, NaClO4

    References
    ^ Associated Press. "Toxic chemical found in California milk". MSNBC. June 22, 2004.
    Associated Press. "State Threatening To Sue Military Over Water Pollution". May 19, 2003.
    "Health Effects Of Perchlorate From Spent Rocket". SpaceDaily.com. July 11, 2002.
    ^ McKee, Maggie. "Perchlorate found in breast milk across US". New Scientist. February 23, 2005

    This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)


  4. victoria

    victoria New Member

    was just reading this in today's paper, glad you posted it! Yep, it is not only dairy, it is in everything! And the gov't wanted to do more studies before releasing this info! Have to wonder why... (I know why, sigh, big business interests)

    IMHO I'd rather err on the side of safety, I don't understand their reluctance to take action. Somewhere I read that humans (and our animals I'm sure) have over 100 chemicals in their bodies that were not there 100 years ago... surely there has to be some interaction and/or effects of all of them! At the very least, it is no surprise our immune systems is affected by perchlorate... and it is interesting they found it specifically in women... and we're the ones that are in these major 'autoimmune diseases'...

    Just my opinion, but I think it is the chemicals plus the stealth pathogens taking advantage of a niche opening up to them as a result.


    all the best,
    Victoria

  5. kjfms

    kjfms Member